AS16-116-18671 (23 April 1972) --- Astronaut Charles M. Duke Jr., lunar module pilot, works at the "Shadow Rock", discovered during the missions third extravehicular activity (EVA) in the area of North Ray Crater (Station 13), April 23, 1972. The scoop, a geological hand tool, leans against the rock. This view was exposed by astronaut John W. Young, commander. The two moon-exploring crew men sampled this rock, which got its name because of a permanently shadowed area it protected. While astronauts Young and Duke descended in the Apollo 16 Lunar Module (LM) "Orion" to explore the Descartes highlands landing site on the moon, astronaut Thomas K. Mattingly II, command module pilot, remained with the Command and Service Modules (CSM) "Casper" in lunar orbit.